JPH0695374B2 - Magnetic head mounting position adjustment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a magnetic head mounting position adjusting device, and more specifically to a magnetic head for adjusting the mounting position of a magnetic head mounted on a rotating cylinder of a magnetic recording / reproducing apparatus. The present invention relates to a mounting position adjusting layer, and particularly to a magnetic head mounting position adjusting device suitable for precisely adjusting the position of a magnetic head with respect to the center of rotation of a cylinder using a fluid dynamic bearing for the cylinder rotation bearing portion. It is a thing.

[Conventional technology]

When attaching a magnetic head to a rotary cylinder used in a magnetic recording / reproducing device such as a VTR, refer to FIG.
That is, as shown in FIG. 10 showing the coupling relationship between the rotary cylinder 1 and the magnetic head 2, the angle index a of the position of each magnetic head 2, 2 from the rotation center of the rotary cylinder 1 and the rotation center Items such as the protrusion amount b and the height C of the magnetic head when the rotary cylinder 1 rotates must be adjusted.
A bearing or a fluid dynamic bearing is used for the bearing portion of the rotary cylinder 1.

When a bearing is used for the bearing portion of the rotary cylinder 1, the position of the magnetic head 2 can be adjusted even after the rotary cylinder 1 and the rotary cylinder are connected.

However, in the case of the rotary cylinder 1 using the fluid dynamic pressure bearing,
The center of rotation is determined only after the rotation of the rotary cylinder 1 is started. When the rotary cylinder 1 is not rotated, the fixed side cylinder and the rotary cylinder are separated by a clearance of 5 to 10 micrometers of the fluid dynamic bearing. The relative position of changes arbitrarily.

Therefore, when a fluid dynamic bearing is used for the bearing portion of the rotary cylinder 1, if the rotary cylinder 1 and the stationary side cylinder are connected, the position adjustment of the magnetic head 2 becomes impossible, and the rotary cylinder 1 alone cannot be adjusted. There is no choice but to adjust the position of the magnetic head 2.

Also, considering that a rotary cylinder is prepared as a service part, even in the case of a rotary cylinder of the type that uses a bearing as a bearing part, the rotary cylinder alone accurately positions the magnetic head to make it compatible with the fixed cylinder. We need to guarantee compatibility.

By the way, in order to adjust the position of the magnetic head 2 by the rotating cylinder 1 alone, the rotating cylinder 1 is set at a predetermined position of the adjusting device.
Must be made coincident with each other, or the center position of the rotary cylinder 1 must be recognized. A conventional apparatus adopting the former method is described in, for example, Japanese Patent Application Laid-Open No. 58-139326, and this method is shown in FIGS. 12 and 13. That is, FIG. 12 is a vertical sectional view of a conventional magnetic head mounting position adjusting device, and FIG. 13 is a sectional view taken along the line AA of FIG.

In FIG. 12, after the rotary cylinder 1 is set on the mounting table 100, air is discharged from the air holes 103 and 104 provided in the fitting portion 101 and the positioning pin 102, and the air pressure causes
As shown in FIG. 3, the bearing assembly hole 3 and the positioning hole 4 provided in the rotary cylinder 1 are positioned uniformly over the entire circumference of the fitting portion 101 and the positioning pin 102. Yes, after positioning as described above, the outflow of air is stopped, the pressurizing unit 105 descends, and the rotary cylinder 1 is sandwiched and fixed between the mounting table 100 and the pressurizing unit 105.

[Problems to be solved by the invention]

However, in the above-mentioned conventional technique, the bearing mounting hole 3
The dimensional error that occurs during the external machining between the rotary cylinder 1 and the rotary cylinder 1 has not been recognized. There is a risk of deviation. That is, when the rotary cylinder 1 is positioned and clamped, it is shown in FIG. 11, that is, a view for explaining the problems in the case where the conventional magnetic head mounting position adjusting device is used, and is shown by reference characters L and M in FIG. Faces are pressed, but these faces
If there is an error in the squareness between L, M and the bearing mounting hole 3, the bearing mounting hole 3 will tilt when the rotary cylinder 1 is clamped, and the position of the magnetic head 2 will be adjusted in this state. Attempts to do this will have a significant effect, especially in the height direction. Further, the adjustment accuracy in the height direction of the magnetic head 2 requires 2-3 micrometers, but this is a value that the above-mentioned squareness occurs with an error of about 20 seconds. Is a value generated when the rotary cylinder 1 is machined. It should be noted that such a problem occurs when the rotary cylinder 1 is positioned and clamped unless the clamping surface is the bearing assembly hole 3 itself. Realization of a mechanism having both is difficult as a practical problem.

In addition, in the rotary cylinder 1 using the fluid dynamic pressure bearing, the bearing assembly hole 3 is replaced by a dynamic pressure bearing portion in which a groove for generating dynamic pressure is processed. Does not like to be scratched, so use this surface to rotate cylinder 1
Can't hold.

The present invention has been made as a result of studies to solve the above-mentioned problems of the conventional technology, and an object thereof is to provide a bearing portion that determines a rotation center of a rotating cylinder and an outer portion of the rotating cylinder. The magnetic head can be accurately positioned with respect to the center of rotation of the rotary cylinder even if there is a relative machining error, which improves the performance of the magnetic recording / reproducing apparatus, homogenizes the quality, and improves the yield of the assembly process. It is an object of the present invention to provide a new magnetic head mounting position adjusting device which has not been heretofore available and which can make a great contribution.

[Means for solving problems]

The above-mentioned purpose is to hold a rotary cylinder and to have a mounting table having a rotation function, a sensor for measuring the distance of the rotary cylinder bearing portion with respect to the rotation angle of the above-mentioned mounting table, and the position of a magnetic head attached to the rotary cylinder. Means and the information from the sensor, and based on the result of calculating the angle between the rotation center axis of the mounting table and the center axis of the rotation cylinder bearing portion, the position information from the magnetic head position measurement means corrects This is achieved by providing a calculator for instructing a magnetic head position adjusting operator of the amount to be adjusted and a display.

That is, the purpose is to measure the bearing center position and the inclination of the center axis of the rotary cylinder in a state where the rotary cylinder is held, calculate the correction amount of the magnetic head adjustment position according to the measured values, and This is achieved by adjusting the position of the magnetic head based on the amount of correction.

[Action]

Here, in order to facilitate understanding, the operation of the device of the present invention described above will be described with reference to FIG. 9, that is, FIG. 9 which is an explanatory view of the principle of the device of the present invention. It is held on a rotary table 9 that can be rotated by °.
Next, the two non-contact displacement gauges 22 are inserted into the bearing portion of the rotary cylinder 1 from above and below. In this state, the rotary mounting table 9 is rotated, and the two non-contact displacement gauges 22, 2 are moved by the displacement sensor.
Measure the distance between 2 and the bearing of rotary cylinder 1 over the entire circumference. The inclination of the bearing center axis of the rotary cylinder 1 relative to the rotation center axis of the rotary mounting table 9 can be calculated by the change in this distance above and below the bearing portion of the rotary cylinder 1, and this axis inclination By shifting the adjustment position of the magnetic head 12 by the correction amount corresponding to, the magnetic head 2 can be adjusted to an accurate position.

As described above, according to the present invention, the magnetic head 2 can be adjusted to an accurate position with reference to the bearing portion of the rotary cylinder 1, even if there is a processing error between the bearing portion and the outer shape of the rotary cylinder 1. It will be possible.

〔Example〕

Hereinafter, the present invention will be described based on an embodiment of FIGS. 1 to 8. FIG. 7 is a longitudinal sectional view of a rotary cylinder 1 to be measured by a magnetic head mounting position adjusting device according to the present invention. In FIG. 7, the rotary cylinder 1 is provided with a bearing hole 4 in the center thereof, which has been subjected to hydrodynamic bearing processing. The magnetic head 2 is attached to a head base 5, and the magnetic head 2 is attached to the rotary cylinder 1 via the head base 5 by an assembling screw 6. As shown in FIG. 8, that is, FIG. 8 which is a partially enlarged view of FIG. 7, the rotary cylinder 1 is provided with an adjusting screw hole 7 on the back side of the head base 5 position. When the adjusting screw 8 attached to the head is rotated, the adjusting screw 8 pushes the head base 5 to deform the head base 5 and change the position of the magnetic head 2 in the height direction.

FIG. 1 is a vertical sectional view showing the overall configuration of the device of the present invention,
In FIG. 1, the rotary mounting table 9 is assembled to the base table 200 via a bearing 10. A gear 11 is provided at the lower end of the rotary mounting table 9, and the rotary mounting table 9 is
A rotational force is applied by a motor 13 via the gear 12.

In addition, a cutout 30 is provided in the upper part of the rotary mounting table 9 to which the claw 15 of the fixing jig 14 that fixes the rotary cylinder 1 is locked. The claw 15 is assembled to the fixing jig 14 via the pin 31. A screw hole 16 is provided in the center of the fixing jig 14, and a pressing shaft 17 is assembled in the screw hole 16. Below the pressing shaft 17, there is a thrust bearing 18
19 is assembled. The state is shown in FIG. That is, FIG. 2 is a plan view of the upper half of FIG.

In the above structure, the operator sets the rotary cylinder 1 on the mounting table 9, and the claws 15 of the fixing jig 14 are cut out of the mounting table 9.
When locked to 30 and rotating the pressing shaft 17, the rotating cylinder 1
Are clamped by the mounting table 9 and the pressing plate 19. A non-contact displacement gauge 22 is attached to the tip of a rod 21 mounted on the cylinder 20 and located at the center of the mounting table 9, and when the rod 21 is taken in and out, the non-contact sensor 22 becomes a rotary cylinder. It is positioned above or below the bearing hole 4.

FIG. 3 is a block diagram of the measuring system of the device of the present invention.

In FIG. 3, the non-contact displacement meter 22 sends a voltage according to the distance from the bearing hole 4 to the data converter 23. Data converter 23
Converts the above voltage into a digital value, and the microprocessor
When sent to the motor 24, the microprocessor 24 causes the motor 13 for rotating the mounting table 9 to rotate the motor 13 by a predetermined angle.
Rotate through. And the microprocessor 24
Data converter 23 every time the motor 13 is rotated by a certain angle.
It internally has a program for reading digital signals from.

On the other hand, the magnetic head 2 is photographed by the television camera 25, and its image is enlarged and displayed on the monitor screen 26. Further, the cursor line 27 is simultaneously displayed on the monitor screen 26, and the cursor line 27 can be moved by the knob 28 in accordance with the image of the magnetic head 2. In addition, the position of the cursor line 27 is set by the operator to transfer the data.
By pressing 29, the digital value is sent to the microprocessor 24, and in this way the microprocessor 24
Can know the height of the magnetic head 2.

Here, the principle of obtaining the tilt angle θ of the rotary cylinder bearing hole 4 and the phase angle α of the tilt with respect to the rotation center of the mounting table 9 in the state where the rotary cylinder 1 is held by the device of the present invention is shown in FIGS. Referring to FIG. 3 and referring to FIGS. 4 and 5, FIGS. 4 and 5 are explanatory views of a measuring system by the device of the present invention.

As shown in FIGS. 1 and 3, the rod of the cylinder 20 is
21 is moved up to position the non-contact displacement gauge 22 attached to the tip of the rod 21 in the lower part of the rotary cylinder bearing hole 4, and the mounting table 9 on which the rotary cylinder 1 is set.
If there is an axis deviation when rotating the
Between the bearing and the bearing of the rotary cylinder 1 (x in FIG. 4).
The distance in the (axis) direction changes like the curve in FIG. In FIG. 4, the rotation angle of the rotary cylinder 1 when the distance between the non-contact displacement gauge 22 and the bearing portion of the rotary cylinder 1 is maximum is θ _D , and the distance at that time is x _D max, The value when the distance becomes the minimum is x _D min. Next, the non-contact displacement gauge 22 is raised by H, and the rotary cylinder 1 is moved in the same manner as above.
Is rotated, the rotation angle of the rotary cylinder 1 when the distance between the non-contact displacement gauge 22 and the bearing portion of the rotary cylinder 1 is maximized is θ _U , the distance at that time is x _U max, and the distance is Assuming that the minimum value is x _U min, θ and α shown in FIG. 5 have the following values.

Next, the entire operation system of the device of the present invention will be described with reference to FIGS.
Referring to FIG. 6 and referring to FIG.
The figure is a flow chart showing the overall operation system of the device of the present invention. First, the operator holds the rotary cylinder 1 on the mounting table 9 as described above. Subsequently, the microprocessor 24 rotates the motor 13 to a position where the image of one of the magnetic heads 2, 2 of the magnetic heads 2, 2 appears on the monitor image 26. Here, the operator turns the knob 28 to align the cursor line 27 with the height position of the magnetic head 2 and then pushes the data transfer button 29 to send the data to the microprocessor 24.

Next, the microprocessor 24 rotates the mounting table 9 by 180 ° by the motor 13, and then the operator turns the knob 28 to align the cursor line 27 with the height position of the magnetic head 2. Then, the data transfer button 29 is pressed again to send the height information of the other magnetic head 2 to the microprocessor 24.

After that, the microprocessor 24 measures the tilt angle of the rotary cylinder bearing hole 4. That is, the microprocessor 24 rotates the motor 13 by a predetermined amount,
In each case, the data concerning the lower part 4 of the bearing hole from the non-contact displacement gauge 22 is received via the data converter 23.

Subsequently, after rotating the mounting table 9 by 360 °, the microprocessor 24 operates the cylinder 20 to position the non-contact sensor 22 on the upper portion of the rotary cylinder bearing hole 4, and then the same operation as described above is performed. Then, the data regarding the upper portion of the bearing hole 4 is received. Based on the upper and lower bearings, the microprocessor 24 calculates the inclination of the central axis of the rotary cylinder bearing hole 4 by the above equation (1). Subsequently, the microprocessor 24 operates on the two magnetic heads 2, 2 which it has received previously.
A correction amount corresponding to the inclination of the central axis is added to the amount of deviation in the height direction of the magnetic head 2 and the magnetic head 2 is displayed to the operator as the amount to be adjusted.

Then, the operator turns the adjusting screw 8 shown in FIG. 8, that is, a partially enlarged view of FIG. 7 with a screwdriver (not shown), and while watching the monitor screen 26, only the above display amount is displayed. , The magnetic head 2 is moved to finish the adjustment.

〔The invention's effect〕

The present invention is as described above, and as is clear from the description of the illustrated embodiments, according to the present invention, the relative machining is performed on the bearing portion that determines the rotation center of the rotary cylinder and the outer shape portion of the rotary cylinder. Even if there is an error, the magnetic head can be accurately positioned with respect to the center of rotation of the rotary cylinder, which greatly contributes to the performance improvement of the magnetic recording / reproducing apparatus, the homogenization of quality, and the improvement of the yield of the assembly process. It is possible to obtain a new magnetic head mounting position adjusting device which is not possible in the past.

[Brief description of drawings]

1 to 8 show an embodiment of the present invention, FIG. 1 is a longitudinal sectional view showing the overall construction of a magnetic head mounting position adjusting device according to the present invention, and FIG. 2 is the upper half of FIG. 3 is a plan view of the part, FIG. 3 is a configuration diagram of a measuring system of the device of the present invention, FIGS. 4 and 5 are explanatory diagrams of a measuring system by the device of the present invention, and FIG. 6 is a flow chart showing an entire operation system of the device of the present invention. FIG. 7 is a longitudinal sectional view of the rotary cylinder 1 to be measured by the device of the present invention, FIG. 8 is a partially enlarged view of FIG. 7, FIG. 9 is an explanatory view of the principle of the device of the present invention, and FIG. FIG. 11 is a perspective view showing the connecting relationship between the rotary cylinder 1 and the magnetic head 2, FIG. 11 is a view for explaining the problems when the conventional magnetic head mounting position adjusting device is used, and FIG. 12 is the conventional magnetic head mounting. FIG. 13 is a vertical sectional view showing a concrete example of the position adjusting device, and FIG. 13 is a sectional view taken along the line AA in FIG. 1 ... Rotary cylinder, 2 ... Magnetic head, 4 ... Rotary cylinder bearing hole, 9 ... Rotary mounting table, 13 ... Motor, 14 ...
… Fixing jig, 22 …… Non-contact displacement meter, 24 …… Microprocessor, 25 …… TV camera, 26 …… Monitor screen.

Claims (1)

[Claims] 1. A mounting table which holds a rotating cylinder and has a rotating function, a sensor for measuring a distance of a rotating cylinder bearing portion with respect to a rotation angle of the mounting table, and a position of a magnetic head attached to the rotating cylinder. Means for measuring, receiving information from the sensor, based on the result of calculating the angle between the rotation center axis of the mounting table and the center axis of the rotating cylinder bearing portion, by the position information from the magnetic head position measuring means, A magnetic head mounting position adjusting device comprising: a computing unit for instructing a magnetic head position adjusting operator of an amount to be corrected; and a display unit.